import std.conv, std.functional, std.range, std.stdio, std.string;
import std.algorithm, std.array, std.bigint, std.bitmanip, std.complex, std.container, std.math, std.mathspecial, std.numeric, std.regex, std.typecons;
import core.bitop;

class EOFException : Throwable { this() { super("EOF"); } }
string[] tokens;
string readToken() { for (; tokens.empty; ) { if (stdin.eof) { throw new EOFException; } tokens = readln.split; } auto token = tokens.front; tokens.popFront; return token; }
int readInt() { return readToken.to!int; }
long readLong() { return readToken.to!long; }
real readReal() { return readToken.to!real; }

bool chmin(T)(ref T t, in T f) { if (t > f) { t = f; return true; } else { return false; } }
bool chmax(T)(ref T t, in T f) { if (t < f) { t = f; return true; } else { return false; } }

int binarySearch(alias pred, T)(in T[] as) { int lo = -1, hi = cast(int)(as.length); for (; lo + 1 < hi; ) { const mid = (lo + hi) >> 1; (unaryFun!pred(as[mid]) ? hi : lo) = mid; } return hi; }
int lowerBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a >= val)); }
int upperBound(T)(in T[] as, T val) { return as.binarySearch!(a => (a > val)); }


enum L = 600;

int N;
int[] ms;

bool build() {
  auto lpf = iota(N + 1).array;
  foreach (p; 2 .. N + 1) if (lpf[p] == p) {
    for (int n = 2 * p; n <= N; n += p) chmin(lpf[n], p);
  }
  int[] as;
  foreach (p; 2 .. N + 1) if (lpf[p] == p) {
    int n = p;
    for (; n * p <= N; n *= p) {}
    as ~= n;
  }
  as.sort;
  const asLen = cast(int)(as.length);
  int k;
  for (k = 0; k < asLen; ++k) {
    if (k + 1 == asLen || as[k] * as[k + 1] > N) {
      break;
    }
  }
  const w = min(k, asLen - k);
  ms = [];
  foreach (i; 0 .. w) {
    ms ~= as[k - 1 - i] * as[k + i];
  }
  ms ~= as[0 .. k - w];
  ms ~= as[k + w .. $];
  ms.sort;
  if (ms.length > L) {
    return false;
  }
  if (ms.length == L) {
    writeln("! N = ", N);
  }
  foreach (m; ms) {
    assert(m <= N);
  }
  return true;
}

void main() {
  /*
  debug {
    for (N = 1; N <= 10^^4; ++N) {
      const res = build;
      // writeln(N, ": ", res);
      if (N <= 30) {
        writeln(ms);
      }
    }
  }
  //*/
  
  N = readInt;
  const res = build;
  assert(res);
  
  int ans = 1;
  foreach (m; ms) {
    writeln("? ", m);
    stdout.flush;
    const g = readInt;
    ans *= g;
  }
  writeln("! ", ans);
  stdout.flush;
}